Rearing trial of Seriola dumerili in a floating cage
Porrello, S.; Andaloro, F.; Vivona, P.; Marino, G. (1993). Rearing trial of Seriola dumerili in a floating cage, in: Barnabé, G. et al. (Ed.) Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. EAS Special Publication, 18: pp. 299-307
In: Barnabé, G.; Kestemont, P. (Ed.) (1993). Production, environment and quality: Proceedings of the International Conference Bordeaux Aquaculture '92, Bordeaux, France, March 25-27, 1992. Special Publication European Aquaculture Society, 18. European Aquaculture Society: Gent. 587 pp., meer
In: Special Publication European Aquaculture Society. European Aquaculture Society: Bredene. ISSN 0774-0689, meer
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| Auteurs | | Top |
- Porrello, S.
- Andaloro, F., meer
- Vivona, P.
- Marino, G.
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| Abstract |
The Mediterranean yellowtail, S. dumerili, is considered a suitable species for intensive aquaculture, for its rapid growth (Giovanardi et al., 1984; Cavaliere et al., 1989) and its high commercial value. This study reports growth and survival results of juveniles reared in a pilot floating cage in the Aeolian Islands (Sicily). The rearing cage was placed 250m off the coast in a sheltered area, on a 12-31m deep bottom. The structure is a hexagonal offshore platform composed of six triangular units with a total area of 60m2 and a total volume of 300m3. Such a modular cage allows easy utilization of one or more rearing units according to the size and number of fishes. The floaters consist of 4.5m long PVC pipes inflated with compressed air at 1.5atm. The structure is completely flexible, without stiff parts. The S. dumerili juveniles (n= 700; bw 72.3g approx. 23) were caught in the Aeolian areas in August 1990 under floating wreckage with a small purse seine and transferred to 1m3 tanks with an open oxygenated water system. Fishes were transferred to one of the triangles of the floating cage at an initial density of 1.66kg.m-3. Ten percent of the total biomass was sampled monthly at random and total length and body weight was recorded. The food ration began at 15% of fish body weight and was gradually decreased to 3.3% during the trial. The fishes reached approximately 857.7g approx. 132.6 of body weight in 120 days with a food conversion index of 4.4. Seasonal temperature variations (12.5-25.5°C) seem to influence growth rate. During the winter, fishes increased by 79g in body weight in 90 days, with a long fasting period. At the end of the trial (15 months) the fishes reached 2.959g approx. 380. The growth rate seemed to be higher in cage systems with trash-fish instead of tanks and dry pellets (Cavaliere et al., 1989). No mortality was observed due to collection and transportation; mortality due to specific pathologies during the rearing period was less than 5%. |
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